Horsehead Nebula - UPDATED with new synthetic luminance approach

[split_city]

Details

Scope: GSO RC8

Mount: EQ6

Imaging camera: Modded Canon 30D, ~10hrs of data (5min exposures) @ ISO1600

Location: Backyard suburb near Adelaide, Australia). Shot over about 8 nights with temperature ranging from 15-25 degrees Celsius.

Lights, darks and flats calibrated in DSS and processing done in CS3.

I have done another reprocess. I generally follow Scott Rosen's workflow which involves using a synthetic luminance image made from the grayscale version of the RGB image. However, I read up that one can identify the best colour channel and use this as a synthetic luminance image. Given this region in mainly Ha, the red channel produced the best SNR. I did however layer mask in the Flame region from the grayscale RGB as it looked better than the one in the red channel.

I had issues with star halos when blending the synthetic luminance and RGB because of differences in star sizes (smaller in luminance compared to RGB). This is a common issue when blending Ha data with RGB data. However, I followed this which simply involved using a Minimum Filter on the stars in the RGB image before combining the synthetic luminance data.

I'm really pleased with the results and think it's an improvement from my previous attempt. Always learning new tricks!

Any feedback is more than welcome

Link here (2MB)

[Stephen Green]

A nice image

Stephen

[stevieR]

Amazing image! Hopefully i will get to that standard some day. You say you took the images over a few nights, sorry if i sound daft but how do you get your equipment setup so that each night its exactly the same image you are taking or does it matter?

[split_city]

Thanks Stephen.

Amazing image! Hopefully i will get to that standard some day. You say you took the images over a few nights, sorry if i sound daft but how do you get your equipment setup so that each night its exactly the same image you are taking or does it matter?

Stevie: Thanks for the praise. Yep taken over several nights. With two young kids, I can't do all night imaging runs. When I'm out, I try and collect between 1-2hrs of data. Given I don't have a permanent setup, I have to polar align my mount each night. I also have to spend some time framing the image to try and get the object of interest roughly in the same position. I use Deep Sky Stacker to stack my images. I tend to have to crop the outer edges as not all images align.

[Gina]

Nice image It will stand the Levels reducing and contrast increased - that will give you an even better image.

[stellawolf]

Super image well done

[ianaiken]

A really nice smooth image good work!

Have you had a look at Sequence Generator Pro? It can do plate solving for your target which means each night once your setup if will slew to your target, plate solve, update the mount with alignment data and center the image very accurately. It can also perform meridian flip and flip PHD guiding calibration data to resume guiding and imaging post flip as well as many other cool helpful things. The plate solving is worthwhile when imaging over multiple nights, it really speeds the whole process up and allows more time for imaging.

[split_city]

Thanks Stella.

A really nice smooth image good work!

Have you had a look at Sequence Generator Pro? It can do plate solving for your target which means each night once your setup if will slew to your target, plate solve, update the mount with alignment data and center the image very accurately. It can also perform meridian flip and flip PHD guiding calibration data to resume guiding and imaging post flip as well as many other cool helpful things. The plate solving is worthwhile when imaging over multiple nights, it really speeds the whole process up and allows more time for imaging.

Hmmm, no I haven't tried it. I will have to look into it. Thanks for the tip.

I can't edit first post but here's the new link for my image.

[Boren]

Nice and smooth!

Cheers,

Harel

[Guest]

Link not working for me.

[split_city]

Thanks Harel.

Sland: click the link a few posts up. You can't edit posts unless you have made 200 posts (or something like that). Very annoying!

[Guest]

Sland: click the link a few posts up. You can't edit posts unless you have made 200 posts (or something like that). Very annoying!

I click the link in the first post I get:

This is not the page you're looking for.

It looks like you're trying to see something in split-city's photostream.

Here are their most recent uploads...

[Guest]

ignore last post - didnt see post a couple above, that works

[split_city]

I understand Sland. I updated the original picture on Flickr but I can't update the link in the opening post because of restrictions set by admin to be able to edit posts. I think one has to have made 200 posts (or something like that) before they are allowed to edit posts. Like I said, very annoying as I think ~200 posts is a bit excessive. But they set the rules. Just go to link in post #8 to see the image.

Dan

[split_city]

haha, you posted that before I did. Now I won't be able to edit my last post!